Geometry of the Electric Dipole

Potential produced by the electric dipole

Potential on the x-y plane

The contour of the potential and the electric force lines produced by an electric dipole

Near field	Far field

The solid curve and the dotted one show the electric force lines and the coutours of the potential on x-y plane, respectively. They are orthogonal with each other.

Electric force lines produced by an electric dipole

Animation of the electric force lines due to the variation of the distance of a positive and a negative charge

Static field is assumed here, in which case the velocity of the field is considered to be infinite. But the velocity of the filed is finite actually. The theory of static field approximate well when the oscillation of charges is slow enough.

Refere "Small dipole" to see electromagnetic wave.